Carb cleaner trick will work on F/I engines as well. But yeah, it will adjust for small air leaks, and beyond that will set a code. In fact, the PCV rupture disc creates a very small air leak, but will usually set a code on these cars, which may sometimes go back off once the car compensates fuel trims for it.I'm probably out to lunch on this but I was wondering if the engine out oxygen sensor would detect a lean condition, if it existed, and compensate by adjusting the fuel trim so a lean code would not be set due to a small intake manifold leak. Additionally, small air leaks in the intake manifold would be compensated by electronic adjustment of the throttle plate position at idle sort of like the idle air control function on older GM products with port fuel injection. Trim compensation can occur within the limitation of the injectors and/or software parameters. Therefore, if the manifold absolute pressure sensor or the mass airflow sensor did not detect an intake manifold leak (per the on board diagnostic calibration), the vehicle would run normally regardless of a small intake manifold leak. In fact, today's engines have such low intake manifold vacuum or even boost, manufactures install vacuum pumps on engines to provide vacuum for power brakes and other vacuum powered equipment. Having said that, the lean condition and carb cleaner trick does apply to engines with carburetors.